(a) Field of Invention
The present invention relates to N-substituted cyclopeptide derivatives with antibacterial and antifungal activity and to a process for their preparation.
(B) Description of the Prior Art
A number of cyclic peptides have been either isolated from natural sources or prepared by classical synthetic methods, for example, see the review by E. Schroder and K .L. Lubke, "The Peptides"; Vol II; Academic Press, New York, 1966, pp424-478.
The present invention discloses novel cyclopeptide derivatives in which a nitrogen atom of the peptide back bone is substituted. These compounds have been found to have the desirable attributes of useful microbial activity coupled with a low order of toxicity.
In addition, a novel process for preparing N-substituted cyclopeptides is disclosed.